Meson vacuum phenomenology in a three-flavor linear sigma model with (axial-)vector mesons

TL;DR

This paper develops a linear sigma model including (axial-)vector mesons to analyze meson properties, achieving a good fit to experimental data and supporting the interpretation of certain scalar mesons above 1 GeV as quark-antiquark states.

Contribution

It introduces a comprehensive three-flavor linear sigma model with (axial-)vector mesons and performs a global fit to meson data, clarifying the quark content of scalar mesons.

Findings

Scalar mesons above 1 GeV are preferred as quark-antiquark states.

The model fits meson masses and decay widths with surprisingly good accuracy.

Axial-vector resonances are also described as quark-antiquark states.

Abstract

We study scalar, pseudoscalar, vector, and axial-vector mesons with non-strange and strange quantum numbers in the framework of a linear sigma model with global chiral $U(N_f)_L \times U(N_f)_R$ symmetry. We perform a global fit of meson masses, decay widths, as well as decay amplitudes. The quality of the fit is, for a hadronic model that does not consider isospin-breaking effects, surprisingly good. We also investigate the question whether the scalar $\bar{q}q$ states lie below or above 1 GeV and find the scalar states above 1 GeV to be preferred as $\bar{q}q$ states. Additionally, we also describe the axial-vector resonances as $\bar{q}q$ states.